Linezolid Zentiva (Linezolid)

Linezolid is used to treat infections caused by resistant Gram‑positive bacteria.

• Methicillin‑resistant Staphylococcus aureus (MRSA) infections: effective therapy for skin, bloodstream and pneumonia caused by MRSA.
• Vancomycin‑resistant Enterococcus (VRE) infections: provides an option for serious VRE infections when alternatives are limited.
• Community‑acquired bacterial pneumonia: achieves bacterial eradication in adult patients with typical and atypical pathogens.
• Skin and soft‑tissue infections: resolves cellulitis, abscesses and wound infections caused by susceptible organisms.

• Linezolid binds to the 50S ribosomal subunit of susceptible bacteria, preventing formation of the initiation complex required for protein synthesis. By blocking the early step of translation, it exerts a bacteriostatic effect against Gram‑positive organisms, including MRSA and VRE. This mechanism allows linezolid to retain activity against strains resistant to other classes of antibiotics.

Linezolid may cause a range of adverse reactions, which are categorized by frequency and severity.

Common Side Effects

• Nausea: mild to moderate gastrointestinal upset.
• Diarrhea: loose stools that may be self‑limiting.
• Headache: transient cranial discomfort.
• Thrombocytopenia: mild reduction in platelet count.
• Rash: skin erythema or maculopapular eruptions.

Serious or Rare Side Effects

• Myelosuppression: severe decrease in blood cell production, including anemia.
• Peripheral neuropathy: nerve damage presenting as tingling or numbness.
• Serotonin syndrome: risk when combined with serotonergic agents, leading to agitation, hyperthermia, and autonomic instability.
• Lactic acidosis: rare metabolic disturbance with elevated lactate levels.

When using linezolid, several precautions should be observed to ensure safe therapy.

• Monitor blood counts: regular CBC testing to detect thrombocytopenia or anemia.
• Assess renal and hepatic function: adjust therapy in patients with significant impairment.
• Avoid concomitant serotonergic drugs: risk of serotonin syndrome requires alternative therapy.
• Use caution in prolonged therapy: extended courses increase risk of myelosuppression and neuropathy.
• Store at 2-8°C: keep refrigerated, protect from light, do not freeze or shake.

Linezolid interacts with several medicines; awareness of major and moderate interactions helps prevent adverse outcomes.

Major Interactions (Avoid)

• Selective serotonin reuptake inhibitors (SSRIs), serotonin‑norepinephrine reuptake inhibitors (SNRIs) and monoamine oxidase inhibitors (MAOIs): may precipitate serotonin syndrome.
• Rifampicin: strong inducer that markedly reduces linezolid plasma concentrations.
• Tyramine‑rich foods and monoamine oxidase inhibitors: risk of hypertensive crisis when combined.

Moderate Interactions (Monitor Closely)

• Warfarin: linezolid may enhance anticoagulant effect, requiring INR monitoring.
• Ethanol: may increase risk of disulfiram‑like reactions.
• Anticonvulsants (e.g., carbamazepine, phenytoin): may lower linezolid levels, necessitating efficacy assessment.